The source of Saturn's kilometric radiation and the magnetic field line's spirality

We put forward a model and deduce the distribution of Saturn's Kilometric Radiation (SKR) Source. The model is as follows, the Kelvin-Helmholtz Instability (KHI) will generate kinds of wave, in which there is the Alfven wave. It will propagate to the Saturn's polar area by following the bending magnetic field line. It will also cause the Cyclotron Maser Instability (CMI) leading to the generation of extraordinary wave (R-X mode) in the process. In our views, the region of the CMI, near the ionosphere of Saturn (1 Saturn radius above the polar area), is regarded as the same area as the Saturn's Kilometric Radiation Source. In this paper, we deduce that the KHI will appear before 11 LT (Saturn's Local Time), the Alfven wave will take 38.3 min to reach Saturn, the sunward magnetic line will bend almost 80°. Finally, we get the distribution of SKR source. It locates from 7-9 LT at a relatively lower latitude to 18 LT at the eveningside.